That’s very explicitly the reason why. When he writes romance it’s done with a level of respect for his female characters that’s rare in fantasy novels in my experience. He doesn’t want to be associated with the FLDS or the ownership of wives by husbands, he wants his female characters to have autonomy and to exert their will on the narrative. And so yeah he’s not even going to give Shallan and Adolin their tall broody (depressed and traumatized) superhero doctor in shining armor boyfriend because of it.

Vin and her boyfriend both pursued each other and worried they’re not good enough for the other. Shallan (whom the fandom ships into a threesome) arranged a political marriage by her skill as a scholar and apprenticeship as a scholar to the Princess before eventually falling in love with her husband who’s smitten with her. And on that note Jasnah is a princess who’s always been more concerned with scholarship than men (very ace coded) and is an atheistic character written with the level of respect he wishes atheists would write religious characters, she’s not foolish, merely incorrect. Then there’s Elantris where Sarene is a princess engaged in political marriage against her father’s wishes, because she sees it as a good move for their kingdom and he’s concerned about her happiness. Warbreaker is the story of a woman rejecting the political marriage she was raised for and her rebellious sister learning to navigate the life she was stuck in as a result.

Also shout out to the gay interspecies relationship in Stormlight between two nerdy men (in the setting scholarship and literacy are considered extremely feminine, which is in itself a feminist statement about men hampering themselves for masculinity)